Sejm and signed on April 1, 1683. It provided for mutual rescue obligation in the event of an enemy attack on either Kraków or Vienna. Indeed, in July, the over 100,000 strong Ottoman army led by Kara Mustafa Pasha laid a siege to Vienna. Hieronim Lubomirski had already been fighting the Turks to help Emperor Leopold, and Sobieski quickly marched his 25,000 men to the Vienna battlefield area, where they complemented an allied army of 70,000 total, comprised also of Austrians and Germans. Sobieski took command of the attack on the besiegers and the main battle took place on September 12, 1683. Heavily involved in the fighting were the Commonwealth infantry, artillery and cavalry. Thousands of the Polish Hussar horsemen were famously involved in the victorious assault on Kara Mustafa's camp. The Ottoman offensive capabilities were broken, even though Kara Mustafa was able to save from the rout a portion of his retreating army. Vienna, the gateway to the West, was spared the fate of Constantinople. The pursuit of the enemy resulted in the two Battles of Párkány. In the first confrontation Sobieski was subjected to a surprise attack, and only two days later, on October 9, together with the Austrians, the Poles destroyed the Turkish army defending the north Hungarian Ottoman possessions. At this juncture, a protectorate by the Commonwealth was sought by the leaders of Hungary, Transylvania and Moldavia. Actively pursuing these relations would require confronting the Habsburg Monarchy. Not willing or able to do so, King John III decided to join the Holy League (1684), an anti-Ottoman alliance and the last European crusade project, consisting also of the papal state, Venice and the Holy Roman Empire. The pact's basic goals were recovery of the lost territories and common fight until the time of a commonly agreed peace. The Holy League arrangements severely limited the Commonwealth's ability to exercise its options and future reverses can be traced to the failure of the decentralized, ineffective Polish diplomacy to protect through negotiations the country's national interest. King Sobieski, euphoric after the Vienna victory, lacked a sense of realistic political judgment. Neglecting the recovery of Kamieniec, he unsuccessfully attacked the Turks in Moldavia. Then pressed by the Emperor's and Pope's diplomacies he agreed, to motivate Russia to join the war with the Ottoman Empire, to an "eternal" peace treaty with the Tsardom, signed in Moscow in 1686. The treaty confirmed and